Three-wire molding-receptacle.



No. 867,440. PATENTED 001". 1,- 1907.

- V J. s. STEWART.

THREE WIRE MOLDING RECBPTAOLE.

APPLICATION FILED JUNE 29. 1906.

2 SHEETS-SHEET 1.

7 0 9 1 1h Tn U 0 D T N E T v A P THREE WIRE MOLDING REGEPTAGLE.

APPLIOATION FILED JUNE 29, 1906- 2 SHEETS-431131 2.

W' memes s. JMW

THE IwRRIs PETERS ca, WASHINGTON, p c.

' UNITED STATES PATENT OFFICE.

JAMES S. STEWART, OF NEW YORK, N. Y., ASSIGNOR TO ANNIE STEWART, OF NEW YORK, N. Y.

THREE-WIRE MOLDING-RECEPTAGLE.

Specification of Letters Patent.

' Patented Oct. 1,1907.

A ears... fil d June 29,1906. serial No. 323,987.

To all whom it may concern:

Be it known that I, J AMES S. STEWART, a citizen of the United States, residing at the city of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Three-Wire Molding-Receptacles, of which the following is a full, clear, and exact description.

My invention relates to lamp receptacles, and particularly receptacles for use with moldings having three circuit wires supplying current to the lamps by the ordinary three-wire system.

The principal object of the invention is to provide a receptacle which can be quickly attached to moldings of this class so as to make the necessary electrical conncctions with either pair of the circuit wires, and furthermore in such a way that the attached receptacle will be symmetrically located on the molding, and have a compact and pleasing appearance.

A further object of the invention is to provide a form of housing for the receptacle which is cheap and efficient, and which has the necessary insulating properties. I also aim to provide a convenient means of attachment for such a housing upon the receptacle.

With these and other objects in view, the invention consists in the construction, combination, in the location and in the arrangement of parts, as hereinafter set forth and shown, and finally particularly pointed out in the appended claims.

In the drawings: Figure 1 is a front view of a receptacle embodying the principles of my invention in position on a three-wire molding; Fig. 2 is a side view of the same; Fig. 3 is a detail sectional view of the housing; Fig. 4 is a side view showing the housing in dotted lines; Fig. 5 is a detail sectional view of the bushing which I employ; Fig. 6 is a front view showing the housing removed; Fig. 7 is a transverse sectional view; Fig. 8 is a detail perspective view of one of the parts; Fig. 9 is a bottom or base view of the porcelain block forming the main body of the receptacle.

In the ordinary three-wire system, the circuit wires are commonly carried by a special molding having three grooves, of which the central groove carries the neutral wire while the outside grooves carry wires at the lamp voltage difference of potential from the central wire. It is, therefore, necessary to connect the lamps between the central wire and either one of the outside wires, and in order to properly distribute the load, it is customary to connect the lamps alternately, first on one side and then on the other. In order to avoid wire connections, it is desirable to have metallic clips on the receptacles which fit into position to engage the proper circuit wires. In my companion application filed herewith, I have set forth a receptacle adapted to make convenient connection with a pair of circuit wires. In the present case I aim to adapt the general principles of my said application to three-wire circuits, and to devise a practical structure which has terminal clips formed to engage the proper circuit Wires and on either branch of the three-wire system as desired. For this purpose I make use of a structure generally similar to that of the above mentioned application, except that the parts are formed so as to be symmetrically disposed on the molding, and at the same time 'to make the necessary connections on either branch. I also provide special insulating means in connection with the above to protect the housing from becoming short circuited on the remaining circuit wire.

Referring now to the drawings and to the various views and reference signs-appearing thereon in which like parts are designated by the same reference sign wherever they occur, 1 indicates a block of porcelain or suitable insulating material, having a flat base 2, and an upper face or surface 3, conveniently parallel with said base. In practice I provide a central protuberance 4, on the face 3, and which serves to position the threaded shell or sleeve 5, which has a hole in its base corresponding to said protuberance.

6 and 7 indicate metallic clips or terminals, each of which is preferably in the form of an angle plate. The two clips are disposed upon the block 1 on opposite sides thereof, so as to be separated by the porcelain. Each of the clips has a terminal screw 8, for making an electrical connection with the circuit wires.

The clip 6 extends over upon the upper face 3 of the block 1, and in this relation serves to clamp the shell 5 in place. The plate has a central hole corresponding to the protuberance 4, and when properly positioned, serves not only as a means for holding the threaded shell or sleeve 5 in place, but as a terminal connection therefor.

9 indicate screws which pass through the block 1 into the upper portion of the clip 6 to hold the same and threaded shell in place. The clip 7 is deflected so as to be capable'of connection with the central stud terminal of the lamp. For this purpose a plate 10 is disposed on the protuberance 4, and fastened thereon by the screw 11, which extends downwardly through the protuberance into the clip 7. The screw 11, therefore, serves to hold the plate 10 and the clip 7 in place, and also as a means of electrical connection between the two.

The disposition of the two clips 6 and 7 may be of any sort suitable for their connection with the circuit wires, but I prefer to have them contained in.curved passages 12 of the block 1, whereby they are protected from grounds or short circuits with any surrounding parts. The circuit wires, indicated at 13, are bared for a short distance, and curved upward, so as to make connections with the terminal screws 8 within said passages 12.

For the purpose of fastening the receptacle upon its supporting molding, I employ a pair of screws 14,

which are received in suitable holes at the two ends of the block 1 for this purpose. The disposition of the screws 14 and the remaining parts on the block 1 is such that when the two screws are passed into the molding symmetrically between the circuit wires on either side, the lamp socket will be symmetrical upon the molding. In other words, the receptacle may be attached to the molding either on one side or on the other, so that the two terminal clips 6 and 7 come above one or the other pair of the circuit wires, but in either case, the threaded shell will be centrally disposed. This permits the same receptacle to be used for connection with either branch of the three wire circuit.

I provide a housing for the receptacle which completely incloses the block 1 and the threaded shell 5. I prefer to make use of a metallic casing 15, which is stamped to fit over the other parts and to be received against the molding. In order that the casing may not by any possibility short circuit the various circuit wires, I arrange ledges 16 on the block 1, against which the lower edges of the casing 15 rest.

17 indicates a plate of insulating material also having ledges 18 and which lies alongside the block 1, so that the ledges 18 lie in alinement with the ledges 16 thereof; This insulating plate is properly held in position by the casing 15 when the latter is suitably positioned thereon.

The casing 15 may be attached to the molding, if desired, but I prefer to make use of a bushing 19 of insulating material, which is internally threaded to engage the threaded shell 5. This bushing may be screwed down upon the threaded shell so as to engage the casing 15 and hold the same in place.

An important feature of my invention relates to the nature of the material used for the casing 15. For this purpose I use metal which is coated with a vitreous coating X such for example, as is employed for porcelain ware or stone ware. This is sufficiently strong and durable and yet has all the necessary insulating properties which are desirable. This form of casing, secured in place by the bushing19, as above described, gives a very compact receptacle of pleasing appearance, and which is symmetrical on the threewire molding. I regard this form of housing as particularly adapted for the present invention, because the nature of the interior parts is such that short circuiting is practically impossible, even if the housing were conductive. This is because although the terminal 6 is not widely removed from the housing, the

. terminal 7, and the terminal circuit wire 13, are very widely separated from the casing, the former by being deeply inset into the block and the latter by the overlying insulating plate 17. Accordingly the metallic stone ware has a particular utility in this connection, and is furthermore practically desirable because of the compact appearance it gives to the complete receptacle in spite of the irregular contour of the interior parts.

What I claim is 1. An electrical appliance adapted to be placed on a three-wire molding and to make electrical connection with two circuit wires thereof, comprising a block of insulating material having a pair of terminal clips thereon, and a sleeve secured to said block at one side of one of said clips and centrally over the other, whereby the sleeve is symmetrically disposed on the molding when the clips are at tached to the circuit wires of either side thereof.

2. An electrical appliance, comprising a block of insulating material having passages therein for two circuit wires of a three-wire system, and a sleeve on said block having its axis vertically above one 01. said pas ages.

3. An electrical appliance, comprising a block of insulating material having a sleeve secured thereto. terminal clips on said block and extending on one side of. the axis of said sleeve, whereby they may be connected to two of the three circuit wires of a molding on which the receptacle is s v1nmetrically placed,

4. An electrical appliance, comprising a block having a sleeve thereon and a central stud terminal, and a pair of metallic clips connected with said sleeve and said terminal and laterally offset therefrom so as to extend into prox imity to two circuit wires of a three-wire system when the receptacle is symmetrically placed on the molding thereof.

5. An electrical receptacle adapted to be placed symmetrically on a threeavire molding to make. electrical conncction with two circuit wires thereof, comprising a block having a sleeve, said block also having a base opposite to one side of the axis of said sleeve, the base having curved passages 011 each side thereof into which a pair of wires ot the three-wire system may project, and a plate having a width corresponding to the width of said base and adapted to be positioned beside the same in use so as to cover up the third wire of the three-wire s tem when the receptacle is placed to have the sleeve symmetrically on the molding.

In witness whereof, I subscribe my signature, in the presence of two witnesses.

MAY BIRD. 

